What your result means
The due date is an estimate, and most dogs whelp within the window shown rather than on the exact day. If your vet has timed ovulation with progesterone tests, choose that method for a much narrower estimate. The milestones show when a vet can confirm the pregnancy and when to start temperature checks before labor.
How to use the Dog Pregnancy Calculator
- Choose what you are counting from: the mating date, or ovulation or the LH surge if your vet tested progesterone.
- Enter the date. If she was mated twice, add the second date too.
- Read the due date, the whelping window and how many days she has been pregnant.
- Open "Show the working" for the milestone dates, and share them with Copy link.
Formula and worked example
from mating: due = mating date + 63 days (normal window: day 56–68)from ovulation: due = ovulation date + 63 days (window day 62–64)from LH surge: due = LH surge date + 65 days (window day 64–66)two matings: window runs from first mating + 56 to last mating + 68
Worked example: a mating on Sunday, March 1, 2026 gives an estimated due date of Sunday, May 3, 2026, with a normal window from Sunday, April 26, 2026 to Friday, May 8, 2026. The range is wide because sperm can survive for several days before ovulation, so the mating date isn't the conception date.
Dog pregnancy week by week
| Week | Days | What happens |
|---|---|---|
| 1 | 1–7 | Fertilization in the oviducts; no visible signs. |
| 2 | 8–14 | Embryos travel to the uterus. |
| 3 | 15–21 | Embryos implant in the uterus around days 20–21. |
| 4 | 22–28 | From about day 25 a vet may confirm pregnancy by ultrasound; it is reliable by days 25–35. |
| 5 | 29–35 | Weight gain and a larger belly start to show. |
| 6 | 36–42 | Appetite increases; talk to your vet about her diet. |
| 7 | 43–49 | Puppies show on an X-ray from about day 45; X-rays after day 55 are best for counting them. |
| 8 | 50–56 | Prepare the whelping box somewhere quiet. |
| 9 | 57–63+ | Take her temperature twice a day from about day 58; a drop usually comes 8–24 hours before delivery. |
Dog pregnancy calendar from a March 1, 2026 mating
| Milestone | Date |
|---|---|
| Implantation (about days 20–21) | Saturday, March 21, 2026 |
| Ultrasound can confirm pregnancy (reliably by days 25–35) | Thursday, March 26, 2026 |
| X-ray shows the puppies (from about day 45; best for counting after day 55) | Wednesday, April 15, 2026 |
| Start taking her temperature twice a day | Tuesday, April 28, 2026 |
| Estimated due date (day 63) | Sunday, May 3, 2026 |
Assumptions and limits
- This is an educational estimate, not veterinary advice. Involve your vet for prenatal care, and call them immediately if labor problems occur.
- Due dates from progesterone-timed ovulation or the LH surge are more precise than dates counted from mating. The MSD Veterinary Manual gives 64–66 days from the LH surge, and a wider 58–72 days counted from the first day she accepted breeding.
- The mating window (56–68 days after a single mating) and the ovulation window (62–64 days) follow Concannon (2000); milestone days assume mating close to ovulation.
- Milestone days are typical ranges; individual dogs and breeds vary.
Frequently asked questions
How long are dogs pregnant?
About 62 to 64 days, or roughly nine weeks. Counted from a single mating the range is wider, about 56 to 68 days, because sperm can survive in the female for several days before the eggs are released and fertilized.
How many months is a dog pregnancy?
A little over two months. At about 63 days, a dog pregnancy lasts around nine weeks, which is why breeders usually plan by weeks and days rather than months.
How accurate is a due date from the mating date?
It gives a useful window but not an exact day, because conception can happen days after mating. Due dates from progesterone-timed ovulation or the LH surge are much more precise, often to within a day or two.
When can a vet confirm a dog is pregnant?
An ultrasound can reliably confirm pregnancy by about 25 to 35 days after mating. The puppies show on an X-ray from about day 45, and X-rays after day 55 are best for counting them. Ask your vet which is best for your dog.
When do dogs start to show pregnancy?
Physical changes usually become noticeable in the second half of pregnancy, from around week five, with weight gain and a rounder belly. Early signs can be subtle, so a vet check is the reliable way to know.
What if she was mated twice?
Enter both dates. The whelping window then runs from 56 days after the first mating to 68 days after the last, which covers either mating being the one that resulted in pregnancy.
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About this calculator
Written and maintained by Ahsan Khan. See how every number is calculated, and the test cases checked on every update, on the methodology page.
Sources
- Whelping and Queening in Bitches and Queens (professional version), MSD Veterinary Manual (Merck Veterinary Manual in the US), Autumn P. Davidson, DVM (accessed Oct 11, 2026)
- Management of Reproduction in Dogs (dog owners version), MSD Veterinary Manual (Merck Veterinary Manual in the US), Autumn P. Davidson, DVM (accessed Oct 11, 2026)
- Canine Pregnancy: Predicting Parturition and Timing Events of Gestation, P. W. Concannon, Recent Advances in Small Animal Reproduction (IVIS), 2000 (accessed Oct 11, 2026)
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Educational estimate, not veterinary advice. Contact your vet for prenatal care, and immediately if labor problems occur.